Brake band construction



Jan. 19, 1932. c. Y. KNIGHT 1,842,102

BRAKE BAND CONSTRUCTION Filed Dec. 1o, 1924 "pml 41 t lilllli 46 [NVENTOR ATTORNEY dan, lill,

stares ATEW CHARLES Y. KNIGHT, 0F PASADENA, CALIFORNIA, ASSIGNOR, BY hDl/,SNTE ASSIGNMENTS,

TO CHESTER, 1i. BRASELTON CORPORATION, OF JERSEY CITY, NEW JERSEY, A COR- PORATION Oli DELAVJARE BRAKE BAND CONSTRUCTION Application filed December 10, 1924. Serial No. 754,936.

'lfhis invention r-lates to a bralre band of the type used for gripping av brake drinn on motor vehicles and similar apparatus.

5in object of the invention is to provide a e band and lining structure which will pr'U ent the squealiing produced under severe operating conditions in the usual type of brakes hereto-fore used, and also to provide a bielre band and lining which will set and cling uniformly on the brake drinn under gentle pressure without severe seizing and resultant shocl.

investigation has apparently indicated that squeaks are caused by hard spots or uneven surfaces in contact with the moving surface of the drum, such, for example, as are caused by the structure of the brake fabric or by the lining securing rivets which either come directly into contact with the surface of the drum or press the immediately surrounding portions of the lining fabric against the drum surface. Unevenness is also caused by a tendency of the brake drum warp to a bell shape at its edges as it becomes het or to wear hollow or unevenly at the center and thus Contact unevenly with the usual flat stiif surface of the brake band lining. I

Accordingly, further objects of the in- `vcntion are to provide means of supporting and securing the lining on the brake band which will prevent contact of the rivets or the immediately surrounding lining, with the brake drum of higher pressure than at other points of the lining; to provide means which will provide uniform, resilient pressure of the iining on the drum; to provide means which will permit the bralie band to conform to the surface of the drum; to provide means which will distribute a powdered or other dry lubricating medium about the lining surface and the drum surface; to provide means which will prevent local high or hard spots, and present smooth, uniform contact surfaces lrretween the drum and the lining; to provide an eijective means for supplying a soft, nietullio or similar lubricating and filling comijiosition to the lining surface; and to provide a structure that will enable the bralres to be applied so as to easily and readily set with a minimum of actuating force.

With these and other objects in view, which may be more readily and fully perceived from the following description, the invention coinf' prises an apparatus described and set forth in the following specification and claims.

The various features of the invention are illustrated in the accompanying drawings,

in which:

Figure l is a side view, partly in section of a portion of a brake drum and a brake band embodying a preferred form of my invention;

Figure 2 is a plan View of a development of a portion of the brake band, portions being broken away to indicate the interior structure of the band and lining;

Figure 3 is a perspective view of a slightly modified form of the band, showing a reinforcing means for the central portion of the band; and

Fig. l is a sectional elevation of a lubrication container for the band.

In my present invention, the brake band is formed or provided with a central portion in which the gripping pressures are transmitted linearly and with a number of transverse or lateral shoulders or wings through which tween the band and the lining, in which any v unevenness is taken up and the lining perinitted to accommodate itself to irregularities in the drum surface.

The lining is secured to the brake band by rivets and the support for the lining is countersunk about the rivets, preferably by cutting away the cork cushion at these places, so that the end of the rivet cannot come into Contact with the drum surface. 'lo insure a smooth, uniform surface for the brake lining, a body of a solid or metallic lubricating and filling medium is mounted in a. portion of the brake band in position to Contact with the surface of the drum so that it is spread and distributed over the surfaces of the brake lining and drum by the relative moven'ient of these surfaces. filling the interstices of the lining fabric and coating the surface of the drum ivith the soft material Which thus provides surfaces free of local hard spots.

Referring` more particularly to the accom panying draivings, the brake band is formed of a strip of metal 10, extending around a brake drum 11 from an upper toggle attachment member 12 to a loiver attachment member 13, and having pairs of transverse kerfs or cuts 14 and 15 at spaced intervals extending inwardly from the opposite side edges of the strip for short distances to a central longitudinal neck portion 1G. The gripping force received from the toggle members is transmitted linearly about the drum through the neck portion 16 and is distributed laterally to shoulder portions 17 and 18 formed between the cuts Af and 15 of adjacent pairs of cuts, the metal of the shoulders being of sufricient stiffness and rigidity to press against the brake drum ivhile the cuts permitthem to give sutliciently to avoid local spots of ei'- treine pressure.

A brake band lining 19 of suitable asbestos fabric construction and of substantially the same Width as the brake band is mounted on the underside of trie band 10, extending throughout the entire surface of the band and pressed against the surface of the brake drum by a central neck portion of the band and by the shoulder portions 17 and 18. The brake lining 19 is attached to the band 1() by means of rivets 2O which are secured in the lining fabric and also in tongues 21 and 22 formed integral With the metal of the band 10 between cuts 14 and 15 of a pair of cuts, the tongues 21 and #22 accordingly lying between pairs of adjacent shoulder portions 17 and 18, respectively.

A layer of cork 23 of substantially the same Width as the brake lining is placed between the lining and the metal band to provide a i .silient cushion which Will permit the lining to yield slightly against the pressure of the brake band. Notches 2d are out from the cork layer immediately beneath each of the tongues 21 and 22 to provide counter-sunk surfaces immediately around the rivets 20 and permit the fabric of the lining and the outer surfaces of the rivets to be drawn inivardly from contact with the surface of the brake drum and thus avoid the formation of any hard spots about the rivets. This construction insures the equal distribution of the pressure exerted by the toggle members 12 and 13 throughout the entire surface of the brake band regardless of any nnevenness in the brake drum, and with a resilient cushion pressure that prevents a too severe gripping or seizing of the brake.

Additional means are provided also for improving the gri'iping action of the brake and preventing the undesirable squeak ordinarily attending the action of braking surfaces, particularly in connection with automobile uses. The means provided for this accon'iplisliment consists in the employment of such soft alloys, metals er other solids as have a lubricating action when placed between braking surfaces, examples of these materials being soft lead and graphite, or suitable alloys or mixtures of metals and graphite.

As effective means of supplying the lead to the area intermediate the friction surfaces of the brake, l utilize a cylindrical block 4:0 ap` plied preferably to the top of the brake band 10 as by rivets Ll1. rlhe block or tube resting directly above an aperture 4-2 formed in the band 10, cork lining 23 and friction lining 19, the aperture terminating adjacent the brake drinn 11; and the interior of the tube etO, is roughened as, for example, by a coarse thread L13 to act as a grater upon the lead, as will be hereinafter described. )i cap #iiis secured in any suitable manner to the top of the tube 4-0 and carries an eye on its lower surface within the tube to which the lead block 1G is resiliently attached by meansy of a coil spring 47, the end of the spring hooking into the eye 45. It is evident that when the vibration is imparted to the tube, the lead block 'will oscillate on its support and contact against tht roughened interior of tho tube, and in this manner small particles of lead are removed from the block and deposited through the aperture upon the surface of the brake drum 11. This lubricant is applied continuously ivhile the support is iu vibration, or in other Words, while the vehicle is in motion and this lubricant effectively spreads over the friction surfaces and prevents squeaking. and greatly improifes in general, the gripping action of the mecliamsm.

An advantageous element of the mechanism also resides in the employment of a bronze block I25 fastened in place of the friction lining 19 adjacent the end of the band 10 beneath the toggle element 12. The bronze plate is extended beyond the end plate 10 bridging the gap intermediate the open ends of the bands 1() and terminating underneath the second toggle member 1?). there being an open area as 2G at the end of the bronze plate permitting longitudinal movement thereof Without interference with the lining members 19 and 23. The end of the bronze segments adjacent the open space 26 is, of course free. The bronze )late 25, as operated by the pressure of the toggles, tends to pull the brake on properly and thus improve the braking action of the brake mechanism as the whole. The placement of the bronze plate 25 so as to operate directly beneath the toggle members 12 and 13, is ad- 7aiihigeous as the ordinary friction material tends to harden from the local high pressure, thus causing noise.

'llo reinforce and strengthen the central neck portion .i6 of the brake band, a reinforcing ring 28 may be mounted and secured on the outer surface of the band by means of lugs or ears 29 through which the ring passes. f his reinforcement is, however, not

fles from the drivers seat, the bronze p, eventing such hardening as would occur fabrics causing squeak and at the same time cooperating efliciently with the remainof Vthe bralre mechanism to transmit an gripping action. Moreover, the

ut' of lubricant, such as lead, supplied in the nov-ei means described, combines i ti the other elements of the invention to bring about highly efcient gripping surface, and to prevent squeak between the' surfaces, this action being accomplished without any damier of n'ielting of the original supply of lead Y analogous lubricant, such as would ordinarily result if the lead were applied as bearing directly on the brake band.

ith the above brake construction, when the brake is applied, the vehicle or other driven mechanism comes to a gradual stop without noise and without the series of rapid gripping and release actions frequently occurring with the usual type of brake under severe strains. The construction of the brake band and lining also insures the highest efficiency n the braking effect and enables the brake to be effectively operated' with a minimum of effort.

described my invention, what l det-hereof at spaced intervals, a brake lining and aplurality of means to attach said lin ing to said band, each of said means being adjacent one of said saw cuts.

2. A brake band having a series of saw cuts ext-ending inwardly from the side edges thereof at spaced intervals, said cuts being arranged in spaced pairs forming tongues between theA cuts of each pair and shoulders between said pairs, a bralre lining and a plurality of means to attach said lining to said band, each of said means being positioned on one of said tongues.

3. A brake band having a series of saw cuts extending inwardly from the side edges thereof at spaced intervals, said cuts being arranged in spaced pairs forming tongues betweenthe cuts of each pair and shoulders between said pairs, said pairs being arranged on opposite sides of a central continuous strip lengthwise of the band, a brake lining and a plurality of means to attach said lining to said band, each of said means being posi tioned on one of said tongues.

4. A brake band having a series of cut-s extending inwardly from the side edges thereof at spaced intervals, and a reinforcement extending lengthwise and centrally of said band.

A brake band having a series of cuts ex tending inwardly from the side edges thereof at spaced intervals, said cuts being arranged in spaced pairs forming tongues between the cuts of each pair and shoulders between said pairs and a brake lining secured to said tongues, said tongues forming the only points of attachment between said band and lining.

6. A bralre band having` a series of cuts eX- tending inwardly from the sides thereof at spaced intervals, said cuts being arranged in spaced pairs forming tongues between the cuts of each pair and shoulders between said pairs, a brake lining, and rivets securing said lining to said tongues, said tongues forming the only points of attachment between said band and lining.

7. A brake band having a series of cuts extending inwardly from the sides thereof at spaced intervals, said cuts being arranged in spaced pairs forming tongues between the cuts of each pair and shoulders between said pairs, a brake lining. means for providing a supporting surface for said lining counter'- sunk at said tongues, and rivets securing and drawing said lining to said tongues.

8. A brake band havin a series of cuts extending` inwardly7 from the sides thereof at spaced intervals, .said cuts being arranged in spaced pairs forming tongues between the cuts of each pair and shoulders between said pairs, a brake lining, a resilient cushion between said lining and said brake band having cut-away portions beneath said tongues, and

ifi

rivets securing said brake lining to said tongues.

9. i bralie band having a series of cuts extending inwa dly from the sides thereof at spaced intervals, said cuts being arranged in spaced pairs forming tongues between the cuts of each pair and shoulders between said pairs, a brake lining, a resilient cushion between said lining and said brake band having cut-away portions beneath said tongue, and means for securing said lining to said tongues and drawing the surface of said lining towards said tongues.

10. A brake band, a lining for said band, a layer of resilient cushion material between said band and said lining, and rivets securing said lining to said band, said layer being cut away around said rivets.

11. A brake band, a lining for said band, a layer of cori; between said band and said lining, and rivets securing said lining to said band, said layer being cut away about said rivets.

1Q. A brake band, a lining for said band, a layer of cork between said band and said lining, said layer having cut-away portions spaced along its outer edges, and means for securing said lining to said band at said cutaway portions.

13. In brake mechanism the combination ot a drum; a split band surrounding and adapted to engage said drum; a guide niember fastened to one end of said band and adapted to engage said drum and to slidably engage and overlap the other end of said band; and power transmitting elements at tached to the end of said band adapted to transmit force to the drum through the guide member.

14. The combination of a brake drum; a brake band operatively disposed therewith; a friction lining interposed between the drum and the band; and an auxiliary metallic friction member adjacent one end of the lining; said metallic friction member being relatively slidable with respect to one end of the band and functioning to distribute forces applied thereto.

15. The combination of a brake drum; a brake band operatively disposed therewitl; a friction lining interposed between the drum and the band; and an auxiliary metallic friction member formed unitarily with one end of the band, said auxiliary member being slidably disposed with respect to the other end of the band and adapted to undergo compressive braking action.

16. rThe combination of a brake drum; a brake band operatively disposed therewith; a friction lining interposed between the drum and the band; and an auxiliary metallic friction member continuous with one end of the lining and adapted to engage the surface of the drum, said auxiliary member being arranged to sustain compressive braking action and distribute evenly te the adjoining drum surface the forces so imparted.

17. The combination of a brake drum; a brake band operatively disposed therewith; a. friction lining secured to the band; and an auxiliary metallic friction member secured to one end of the band and slidably disposed with respect to the other, said lining and auxiliary member being interposed between the drum and band and adapted to wrap completely about the drum, thereby impara ing braking action to the entire periphery of the drum,

1S. rPhe combination of a brake drum; a friction lining partially surrounding the periphery ot the drum; a brake band united with the lining and engageable with a portion of the drum; and an auxiliary metallic friction member secured to one end of the band and adapted to engage a portion of the drum left exposed by the lining, said auxiliary friction member being adapted to un dergo compressive frictional engagement with said drum.

19. The combination of a brake drum; a friction lining partially surrounding the periphery of the drum; an auxiliary metallic friction member; and a brake band securely united with the lining and with one end ot the auxiliary member the other end thereotl being slidably disposed with respect to the band and adapted to be compressed into engagement with the drum.

In testimony whereof, I aitix my signature.

CHARLES Y. KNGHT. 

